There is known a technology for an inverter to generate an AC voltage by performing switching and apply the AC voltage to a motor thereby controlling the motor current. In such an inverter, to prevent a short circuit in upper and lower arms, a dead time in which the upper and lower arms are both off at the same time is provided. During this dead time, the fluctuation in inverter output voltage occurs; however, in PTL 1, there is described a technology for compensating for such fluctuation in inverter output voltage.
In PTL 1, there is described a configuration for calculating a phase of a fundamental wave of motor current on the basis of a dq-axis current command and a rotation angle of the motor, estimating the polarity of the motor current during a dead time on the basis of the phase, and outputting a dead time compensation voltage stored in a memory in a feedforward control method.
Furthermore, in PTL 2, there is described a technology for determining the presence or absence of dead time compensation on the basis of the average value of motor current or the value of a fundamental wave and the polarity of the peak value of high-frequency ripple.